Apparatus and methods for isolating a reaction chamber from a loading chamber resulting in reduced contamination

ABSTRACT

The present disclosure relates to a semiconductor processing apparatus having a reaction chamber which can include a baseplate having an opening; a moveable substrate support configured to support a substrate; a movement element configured to move a substrate held on the substrate support towards the opening of the baseplate; a plurality of gas inlets positioned above and configured to direct gas downwardly towards the substrate support; and a sealing element configured to form a seal between the baseplate and the substrate support, the seal positioned at a greater radial distance from a center of the substrate support than an outer edge of the substrate support. In some embodiments, the sealing element can also include a plurality of apertures extend through the sealing element, the apertures configured to provide a flow path between a position below the sealing element to a position above the sealing element.

BACKGROUND Field of the Disclosure

The present disclosure relates to systems and methods for handling andprocessing semiconductor substrates and, in particular, to reactors usedfor the fabrication of thin films.

Description of the Related Art

In the processing of semiconductor devices, such as transistors, diodes,and integrated circuits, a plurality of such devices are typicallyfabricated simultaneously on a thin slice of semiconductor material,termed a substrate, wafer, or workpiece. The fabrication processincludes, among other steps, vapor deposition for depositing thin filmson surfaces of substrates. These methods include vacuum evaporationdeposition, Molecular Beam Epitaxy (MBE), different variants of ChemicalVapor Deposition (CVD) (including low-pressure and organometallic CVDand plasma-enhanced CVD), and Atomic Layer Deposition (ALD).

In an ALD process, one or more substrates with at least one surface tobe coated are introduced into a deposition chamber. The substrate isheated to a desired temperature, typically above the condensationtemperatures of the selected vapor phase reactants and below theirthermal decomposition temperatures. One reactant is capable of reactingwith the adsorbed species of a prior reactant to form a desired producton the substrate surface. Two, three or more reactants are provided tothe substrate, typically in spatially and temporally separated pulses.

In an example, in a first pulse, a first reactant representing aprecursor material is adsorbed largely intact in a self-limiting processon a wafer. The process is self-limiting because the vapor phaseprecursor cannot react with or adsorb upon the adsorbed portion of theprecursor. After any remaining first reactant is removed from the waferor chamber, the adsorbed precursor material on the substrate reactedwith a subsequent reactant pulse to form no more than a single molecularlayer of the desired material. The subsequent reactant may, e.g., stripligands from the adsorbed precursor material to make the surfacereactive again, replace ligands and leave additional material for acompound, etc. In an unadulterated ALD process, less than a monolayer isformed per cycle on average due to steric hindrance, whereby the size ofthe precursor molecules prevent access to adsorption sites on thesubstrate, which may become available in subsequent cycles. Thickerfilms are produced through repeated growth cycles until the targetthickness is achieved. Growth rate is often provided in terms ofangstroms per cycle because in theory the growth depends solely onnumber of cycles, and has no dependence upon mass supplied ortemperature, as long as each pulse is saturative and the temperature iswithin the ideal ALD temperature window for those reactants (no thermaldecomposition and no condensation).

Reactants and temperatures are typically selected to avoid bothcondensation and thermal decomposition of the reactants during theprocess, such that chemical reaction is responsible for growth throughmultiple cycles. However, in certain variations on ALD processing,conditions can be selected to vary growth rates per cycle, possiblybeyond one molecular monolayer per cycle, by utilizing hybrid CVD andALD reaction mechanisms. Other variations maybe allow some amount ofspatial and/or temporal overlap between the reactants. In ALD andvariations thereof, two, three, four or more reactants can be suppliedin sequence in a single cycle, and the content of each cycle can bevaried to tailor composition.

During a typical ALD process, the reactant pulses, all of which are invapor form, are pulsed sequentially into a reaction space (e.g.,reaction chamber) with removal steps between reactant pulses to avoiddirect interaction between reactants in the vapor phase. For example,inert gas pulses or “purge” pulses can be provided between the pulses ofreactants. The inert gas purges the chamber of one reactant pulse beforethe next reactant pulse to avoid gas phase mixing. To obtain aself-limiting growth, a sufficient amount of each precursor is providedto saturate the substrate. As the growth rate in each cycle of a trueALD process is self-limiting, the rate of growth is proportional to therepetition rate of the reaction sequences rather than to the flux ofreactant.

When implementing ALD or other deposition processes, it is desirablethat the workpiece does not become contaminated by particulates, whichmay lead to device failure. Accordingly, reactors in which workpiecesare processed are typically sealed to prevent contamination from theexterior of the reaction space from entering the reaction space and toprevent reactants and reactant byproducts from escaping to the exteriorof the reaction space.

SUMMARY

According to one embodiment, a semiconductor processing apparatus isprovided. The semiconductor processing apparatus comprises a reactionchamber comprising a baseplate including an opening, a moveablesubstrate support configured to support a substrate, a movement elementconfigured to move a substrate held on the substrate support towards theopening of the baseplate, a plurality of gas inlets positioned above andconfigured to direct gas downwardly towards the substrate support, and asealing element configured to form a seal between the baseplate and thesubstrate support, the seal positioned at a greater radial distance froma center of the substrate support than an outer edge of the substratesupport.

According to certain embodiments, each aperture can comprise a slot, andthe plurality of apertures can be spaced around an outer edge of thesealing element. The apparatus can further comprise a second pluralityof slots arranged on a radially inner portion of the sealing element.

According to one embodiment, a semiconductor processing apparatuscomprises a reaction chamber comprising a baseplate including anopening, a moveable substrate support configured to support a substrate,a movement element configured to move a substrate held on the substratesupport towards the opening of the baseplate, and a metal sealingelement extending around the substrate support and configured to form aseal between the baseplate and the substrate support. A plurality ofapertures extend through the sealing element, the apertures configuredto provide a flow path between a position below the sealing element to aposition above the sealing element.

According to certain embodiments, each aperture can comprise a slot, andthe plurality of apertures can be spaced around an outer edge of thesealing element. The apparatus can further comprise a second pluralityof slots arranged on a radially inner portion of the sealing element.

According to one embodiment, a semiconductor processing apparatuscomprises a reaction chamber comprising a baseplate including anopening, a moveable substrate support comprising a substrate retentionportion configured to support a substrate, a movement element configuredto move a substrate held on the substrate support towards the opening ofthe baseplate, and a sealing element configured to form a seal betweenthe baseplate and the substrate support. The seal is positioned radiallyfrom a center of the substrate support at a distance at least 30% orgreater than the distance between the center of the substrate supportand an outer edge of the substrate retention portion. A plurality ofapertures extend through the sealing element, the apertures configuredto provide a flow path between a position below the sealing element to aposition above the sealing element.

For purposes of summarizing the invention and the advantages achievedover the prior art, certain objects and advantages of the invention havebeen described herein above. Of course, it is to be understood that notnecessarily all such objects or advantages may be achieved in accordancewith any particular embodiment of the invention. Thus, for example,those skilled in the art will recognize that the invention may beembodied or carried out in a manner that achieves or optimizes oneadvantage or group of advantages as taught herein without necessarilyachieving other objects or advantages as may be taught or suggestedherein.

All of these embodiments are intended to be within the scope of theinvention herein disclosed. These and other embodiments of the presentinvention will become readily apparent to those skilled in the art fromthe following detailed description of the preferred embodiments havingreference to the attached figures, the invention not being limited toany particular preferred embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the inventiondisclosed herein are described below with reference to the drawings ofsome embodiments, which are intended to illustrate and not to limit theinvention.

FIG. 1 is a perspective, cross-sectional view of an embodiment of asemiconductor processing apparatus.

FIG. 2A is a front, cross-sectional view of an embodiment of thesemiconductor processing apparatus of FIG. 1.

FIG. 2B is a front, cross-sectional view of an embodiment of a portionof the semiconductor processing apparatus of FIG. 1.

FIG. 3A is an enlarged, cross sectional view of a contact seal isolatingthe loading chamber from the reaction chamber according to an embodimentof a semiconductor processing apparatus.

FIG. 3B is an enlarged view of a portion of FIG. 3A.

FIG. 3C is an enlarged view similar to FIG. 3B but of an embodiment witha baseplate having a curved surface.

FIG. 3D is a top view of a sealing element according to an embodiment.

FIG. 4 is an enlarged, cross sectional view of a seal isolating theloading chamber from the reaction chamber according to an embodiment ofa semiconductor processing apparatus.

FIG. 5 is an enlarged, cross sectional view of a seal isolating theloading chamber from the reaction chamber according to an embodiment ofa semiconductor processing apparatus.

FIG. 6 is an enlarged, cross sectional view of a seal isolating theloading chamber from the reaction chamber according to an embodiment ofa semiconductor processing apparatus.

FIG. 7 is an enlarged, cross sectional view of a seal isolating theloading chamber from the reaction chamber according to an embodiment ofa semiconductor processing apparatus.

DETAILED DESCRIPTION

Although certain embodiments and examples are disclosed below, it willbe understood by those in the art that the invention extends beyond thespecifically disclosed embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Thus, it is intended thatthe scope of the invention herein disclosed should not be limited by theparticular disclosed embodiments described below.

In vapor or gas deposition processes, it can be important to provideuniform deposition across the width or major surface of the substrate(e.g., a semiconductor wafer). Uniform deposition ensures that depositedlayers have the same thickness and/or chemical composition across thesubstrate, which improves the yield of integrated devices (e.g.,processors, memory devices, etc.), and therefore the profitability persubstrate. During such deposition processes, it can also be important toavoid exposure of the substrate and the reaction chamber from reactionbyproducts, particulates, or other contaminants, to similarly improveyield and profitability.

The embodiments disclosed herein can be utilized with semiconductorprocessing devices configured for any suitable gas or vapor depositionprocess. For example, the illustrated embodiments show various systemsfor depositing material on a substrate using atomic layer deposition(ALD) techniques. Among vapor deposition techniques, ALD has manyadvantages, including high conformality at low temperatures and finecontrol of composition during the process. ALD type processes are basedon controlled, self-limiting surface reactions of precursor chemicals.Gas phase reactions are avoided by feeding the precursors alternatelyand sequentially into the reaction chamber. Vapor phase reactants areseparated from each other in the reaction chamber, for example, byremoving excess reactants and/or reactant by-products from the reactionchamber between reactant pulses. Removal can be accomplished by avariety of techniques, including purging and/or lowering pressurebetween pulses. Pulses can be sequential in a continuous flow, or thereactor can be isolated and can backfilled for each pulse.

Briefly, a substrate is loaded into a reaction chamber and is heated toa suitable deposition temperature, generally at lowered pressure.Deposition temperatures are typically maintained below the precursorthermal decomposition temperature but at a high enough level to avoidcondensation of reactants and to provide the activation energy for thedesired surface reactions. Of course, the appropriate temperature windowfor any given ALD reaction will depend upon the surface termination andreactant species involved.

A first reactant is conducted into the chamber in the form of vaporphase pulse and contacted with the surface of a substrate. Conditionsare preferably selected such that no more than about one monolayer ofthe precursor is adsorbed on the substrate surface in a self-limitingmanner. Excess first reactant and reaction byproducts, if any, arepurged from the reaction chamber, often with a pulse of inert gas suchas nitrogen or argon.

Purging the reaction chamber means that vapor phase precursors and/orvapor phase byproducts are removed from the reaction chamber such as byevacuating the chamber with a vacuum pump and/or by replacing the gasinside the reactor with an inert gas such as argon or nitrogen. Typicalpurging times for a single wafer reactor are from about 0.05 to 20seconds, more preferably between about 1 and 10 seconds, and still morepreferably between about 1 and 2 seconds. However, other purge times canbe utilized if desired, such as when depositing layers over extremelyhigh aspect ratio structures or other structures with complex surfacemorphology is needed, or when a high volume batch reactor is employed.The appropriate pulsing times can be readily determined by the skilledartisan based on the particular circumstances.

A second gaseous reactant is pulsed into the chamber where it reactswith the first reactant bound to the surface. Excess second reactant andgaseous by-products of the surface reaction are purged out of thereaction chamber, preferably with the aid of an inert gas. The steps ofpulsing and purging are repeated until a thin film of the desiredthickness has been formed on the substrate, with each cycle leaving nomore than a molecular monolayer. Some ALD processes can have morecomplex sequences with three or more precursor pulses alternated, whereeach precursor contributes elements to the growing film. Reactants canalso be supplied in their own pulses or with precursor pulses to stripor getter adhered ligands and/or free by-product, rather than contributeelements to the film. Additionally, not all cycles need to be identical.For example, a binary film can be doped with a third element byinfrequent addition of a third reactant pulse, e.g., every fifth cycle,in order to control stoichiometry of the film, and the frequency canchange during the deposition in order to grade film composition.Moreover, while described as starting with an adsorbing reactant, somerecipes may start with the other reactant or with a separate surfacetreatment, for example to ensure maximal reaction sites to initiate theALD reactions (e.g., for certain recipes, a water pulse can providehydroxyl groups on the substrate to enhance reactivity for certain ALDprecursors).

As mentioned above, each pulse or phase of each cycle is preferablyself-limiting. An excess of reactant precursors is supplied in eachphase to saturate the susceptible structure surfaces. Surface saturationensures reactant occupation of all available reactive sites (subject,for example, to physical size or steric hindrance restraints) and thusensures excellent step coverage over any topography on the substrate. Insome arrangements, the degree of self-limiting behavior can be adjustedby, e.g., allowing some overlap of reactant pulses to trade offdeposition speed (by allowing some CVD-type reactions) againstconformality. Ideal ALD conditions with reactants well separated in timeand space provide near perfect self-limiting behavior and thus maximumconformality, but steric hindrance results in less than one molecularlayer per cycle. Limited CVD reactions mixed with the self-limiting ALDreactions can raise the deposition speed. While embodiments describedherein are particularly advantageous for sequentially pulsed depositiontechniques, like ALD and mixed-mode ALD/CVD, the embodiments herein canalso be employed for pulsed or continuous CVD, or other semiconductorprocesses.

Examples of suitable reactors that may be used include commerciallyavailable ALD equipment such as any of the EmerALD®, Synergis®, orEagle® series reactors, available from ASM International of Almere, theNetherlands. Many other kinds of reactors capable of ALD growth of thinfilms, including CVD reactors equipped with appropriate equipment andmeans for pulsing the precursors, can be employed. In some embodiments,a flow type ALD reactor is used, as compared to a backfilled reactor.For example, a plurality of inlets designed to evenly distribute gasinto the reaction space may be implemented. For example, a dispersionmechanism such as a showerhead assembly may be implemented above asingle-wafer reaction space.

The ALD processes can optionally be carried out in a reactor or reactionspace connected to a cluster tool. In a cluster tool, because eachreaction space is dedicated to one type of process, the temperature ofthe reaction space in each module can be kept constant, which improvesthe throughput compared to a reactor in which is the substrate is heatedto the process temperature before each run. A stand-alone reactor can beequipped with a load-lock. In that case, it is not necessary to cooldown the reaction space between each run. These processes can also becarried out in a reactor designed to process multiple substratessimultaneously, e.g., a mini-batch type showerhead reactor.

Some known semiconductor deposition apparatus designs include an upperprocessing chamber configured for horizontal reactant flow parallel tothe surface of the wafer, and a lower loading chamber. A gap isconfigured between the two chambers configured to provide flowtherethrough. The gap reduces inert gas purge flow from the lowerchamber into the upper chamber, while also reducing diffusion of processbyproducts from the reaction space into the lower chamber. However,these conventional designs are not effective for recent depositionprocesses which use increased gas flow rates. This is because the higherflow rates increase the pressure in the reaction chamber, and in turn,the loading chamber pressure is increased to prevent process chemistryfrom migrating into the lower chamber. The higher loading chamberpressure results in higher flow from the lower chamber into the processspace, which further raises the process pressure and dilutes the processchemistry at the edge of the wafer, resulting in depositionnon-uniformity and waste. Additionally, the existing inert gas purgepath from the lower chamber into the upper chamber is very close to thewafer edge which can cause flow disturbances. These flow disturbancescan in turn impact process deposition uniformity and/or generateparticles. Soft seals, such as elastomeric O-rings that might be usedfor creating an isolating seal, cannot work at high processtemperatures.

Described herein are embodiments of a sealing element that can beimplemented to provide a seal between a process (e.g., upper) chamberand a loading (e.g., lower) chamber of a semiconductor processingapparatus. The sealing element can be configured such that when theprocess and loading chambers are moved to a processing position, a sealis formed between the two chambers. The sealing element is configured,for example, with apertures of a controlled size, shape, positioningand/or quantity, such that when the seal is formed, a controlled amountof gas can still flow between the two chambers. This configuration isdifferent from the aforementioned conventional systems that do not haveany sealing element, do not have direct sealing contact between theupper or lower chamber, and which maintain an unobstructed flow path viaa gap between the two chambers.

Embodiments herein can provide a soft, flexible, contact seal to improveisolation of the loading chamber from the reaction chamber. The sealingelement can provide a metal-to-metal contact seal providing controlledisolation between the two chambers. Although not a perfect seal, theembodiments can significantly reduce the flow from the lower chamberinto the process space, and reduces diffusion from the process spaceinto the lower chamber, improving process uniformity. The seal can bepositioned further away radially from the edge of the substrate,relative to conventional processes, to also improve process uniformityand prevent contamination, for example, at the wafer edge. For example,the seal can be positioned proximate to the vacuum exhaust ports.Positioning the seal further from the edge of the substrate can alsoaddress concerns for particle generation that may occur at the sealcontact area. A controlled flow of inert gas, via control of theconfiguration of the apertures in the sealing element, can provide avery low-flow purge to further reduce diffusion from the reactionchamber into the lower chamber. This purge flow can enter the reactionspace at the outer edge of the reaction space (e.g., beyond the outerperimeter of the shower head) such that it does not disrupt the processgases close to the wafers edge, and thus does not affect processuniformity. The materials for the sealing element can be selected forcompatibility with various process chemistries and temperatures.Examples of materials that can be used are hastelloy C22 and Grade 2titanium. The sealing element can also be coated to further improvecorrosion resistance (e.g. with Al2O3 deposited by ALD). Made of metal,the sealing element can handle high process temperatures (e.g. 680 C).The same hardware that is used to attach the sealing element to theperimeter of the substrate support can also be used to support a thermalisolation shield. The shield covers the underside of the susceptorsupport and heater to improve thermal uniformity.

FIG. 1 shows a perspective cross-sectional view of a semiconductorprocessing apparatus 100 comprising a loading chamber 101 and a reactionchamber 102, with a sealing element 114 positioned therebetween.Together, the loading chamber 101 and the reaction chamber 102 can beconsidered a process module. In the illustrated embodiment, the reactionchamber 101 is disposed above the loading chamber 102.

The reaction chamber 102 can comprise an inlet 105 and an outlet 107.The reaction chamber 102 can comprise a plurality of inlets 105. In someembodiments, the reaction chamber 102 can comprise a plurality ofoutlets 107. Gases such as reactants and purge gases can flow into thechamber 102 through the inlet 105. Outlet 107 can comprise an exhaustport to allow gases such as excess reactants, reactant byproducts, andpurge gases to flow out of the chamber 102 through the outlet 107. Thereaction chamber 102 can be configured as a single-wafer vertical flowreaction chamber. The reaction chamber can be configured as a gas orvapor deposition chamber, such as an ALD chamber.

The loading chamber 101 may comprise one or more inlets 104 and one ormore outlets. In operation, gases such as purge gases may flow into theloading chamber 101 through the loading chamber inlet 104. The loadingchamber outlet can comprise an exhaust port to allow gases such asexcess reactants, reactant byproducts, and purge gases to flow out ofthe loading chamber 101. The reaction chamber outlet can be configuredto exhaust gases from a position below the reaction chamber 102, andthus may be separate from the reaction chamber outlet 107. In someembodiments, the loading chamber may not have an exhaust outlet separatefrom the reaction chamber outlet 107. In some embodiments, gases mayflow from the loading chamber, into and through the reaction chamber,and exhaust out of the reaction chamber outlet 107. The loading chambercan comprise a gate valve 111. The gate valve 111 can allow for loadingand unloading of substrates to and from the loading chamber 101. Thegate valve 111 may allow access into the loading chamber 101, forexample, from a transfer chamber, load lock, processing chamber, cleanroom, etc. The depicted configuration, such as the positions of the gatevalve 111, inlets 104, 105 and outlet 107 are illustrative, and may beadjusted based on, for example, the process to be performed in thereaction chamber 102, the desired flow path of the gases, etc. Forexample, inlet 104 to the loading chamber can be separate from the gatevalve 111.

The apparatus 100 can comprise a substrate support 108 configured toreceive and support a substrate, such as a semiconductor workpiece W(e.g., a silicon wafer). The workpiece W may be loaded and unloaded ontoand off of the substrate support 108 in various ways, such as with anend effector of a robot. The substrate support 108 can comprise asubstrate retention portion of various configurations. For example, thesubstrate support 108 may comprise lift-pins and/or cutouts to aid inloading and unloading of the workpiece W with a paddle or fork. Thesubstrate support 108 may comprise a vacuum system that holds theworkpiece W in place after loading, or gravity alone may hold theworkpiece W. The substrate retention portion can comprise a recess 109formed in its upper surface that is sized and shaped to hold theworkpiece W. In some embodiments, the recess 109 is between 300 mm and500 mm in diameter. In some embodiments, the recess 109 is between 300mm and 305 mm in diameter. In some embodiments, the recess 109 isbetween 450 mm and 455 mm in diameter. In some embodiments, thesubstrate support 108 can comprise materials including hastelloy C22 orGrade 2 titanium. The substrate support 108 can comprise a coating ofAL203. The substrate support 108 can be moveable between a loading and aprocessing position, as described presently.

FIGS. 2A and 2B show front cross-sectional views of the semiconductorprocessing apparatus 100 from FIG. 1. FIG. 2A shows the apparatus 100with the substrate support 108 in a processing (e.g. raised or upper)position. FIG. 2B depicts the substrate support 108 in a loading (e.g.,lowered or lower) position. As shown, the reaction chamber 102 cancomprise a baseplate 112 with an opening 150. The baseplate 112 and itsopening 150 can be positioned approximately between a loading space 121within the loading chamber 101 and a reaction zone 122 within thereaction chamber 102.

The apparatus 100 can comprise a movement element 110 configured to movethe substrate support 108, and thus a workpiece W disposed on thesubstrate support 108, towards and away from the opening 150. Thus, themovement element 110 can move the substrate support 108 between theprocessing position shown in FIG. 2A and the loading position shown inFIG. 2B. When the substrate support 108 is in the processing position,the reaction zone 122 can be formed, to allow processing within thechamber 102. The movement element 110 can be configured to move thesubstrate support 108 towards the opening 150 to form a seal between theinterior of the chamber 102 and the exterior of the chamber 102 (such asthe loading chamber 101), as described further below. The movementelement 110 can comprise any suitable drive mechanism configured to movethe substrate support 108.

As described above, the reaction chamber 102 can be configured toinclude the plurality of inlets 105. Inlets 105 can be configured todirect gasses in a downward flow (e.g., showerhead) formation. Forexample, the inlet or inlets 105 can direct gasses at some substantiallynon-parallel (e.g., non-horizontal) angle relative to a substantiallyplanar upper surface of the substrate support 108 and substrate Wpositioned on the support 108. In this way, the inlets 105 can beconfigured to form a substantially downward, non-parallel flow path ofgases towards the substrate support 108 and substrate W.

The inlets and outlets can be advantageously positioned, to reducecontamination and improve uniformity, in combination with the sealingfeatures described herein. For example, the inlets 105 can be disposedradially inwardly from the outlets 107 (relative to a centerline 900 ofthe substrate support 108). In some embodiments, the outlet 107 cancomprise an exhaust ring with a ring shape, such as a ring-shaped cavityformed in the upper portion of the apparatus 100. The exhaust ring canextend around the substrate support 108. In some embodiments where theoutlet 107 is a ring-shaped cavity, the outlet 107 can be disposed abovethe radially outer-most edge of reaction chamber 102. The outlet 107 canexhaust gasses from the reaction chamber 102. In some embodiments, allof the inlets 105 are disposed radially inwardly from the radiallyinner-most edge of the baseplate 112. In some embodiments, all of theinlets 105 are disposed radially inwardly from the radially outer-mostedge of the substrate support 108.

The apparatus 100 can be configured to provide semiconductor fabricationprocesses that involve high reactor pressures and/or high flow rates, asdescribed above. Moreover, some processes can include rapid changes inpressure and/or flow rates. In such scenarios, as described above, itcan be beneficial to control or restrict the amount of flow between theloading chamber 101 and the reactor chamber 102 or vice versa, to avoidcontamination and/or improve process uniformity. For example, it may bedesirable to provide a hermetic seal between the loading chamber 101 andthe reactor chamber 102, when the apparatus 100 is in a processingposition. In some embodiments, it may be desirable to provide a sealbetween the loading chamber 101 and the reactor chamber 102 that allowssome amount of flow therebetween, without providing a fully hermeticseal.

Embodiments of the sealing element described herein can provide theseand other benefits and functionality. For example, the sealing elementscan substantially restrict or completely close a flow path between theloading chamber and the reaction chamber. As shown in FIG. 2A, thesealing element 114 can be configured to form a seal between thebaseplate 112 and the substrate support 108, such that the processingchamber 102 and the loading chamber 101 are substantially sealedrelative to each other. The sealing element 114 can comprise metal. Thesealing element 114 can comprise a flexible material, to provide aflexible diaphragm structure. For example, the sealing element 114 cancomprise a material with a Young's Modulus between about 11,000 ksi to32,000 ksi, to provide said flexibility. The sealing element cancomprise a formed metal sheet with a thickness between about 1 mm andabout 3 mm to provide said flexibility. In some embodiments, the sealingelement 114 can comprise materials including, but not limited tohastelloy C22 or Grade 2 titanium. The sealing element 114 can comprisea coating of at least one of Al₂O₃, ZrO, or Yttrium Oxide.

FIGS. 3A-3D illustrate the how the sealing element 114 interacts withthe baseplate 112 and substrate support 108 to form a seal according toan embodiment of a semiconductor processing apparatus 100.

FIG. 3A shows an enlarged view of a portion of the apparatus 100 in FIG.2A, in a processing position, with an embodiment of the sealing element114. The apparatus 100 can comprise a gap that provides a flowpath, suchas a gap 116 and a flowpath 901, between the processing chamber 102 andthe loading chamber 101, when the apparatus 100 is in the processingposition. For example, the gap 116 can be disposed between the substratesupport 108 and the baseplate 112. The gap 116 can extend radially(e.g., horizontally) between the substrate support 108 and the baseplate112 as shown. In some embodiments, the substrate support 108 andbaseplate 112 can be configured to lack any vertical gap between thesetwo components. For example, the inner perimeter of baseplate 112 can belocated at a greater radial position than an outer perimeter of thesubstrate support 108. In such embodiments, the seals describedelsewhere herein can be formed without a substantial vertical gapbetween the substrate support 108 and the baseplate 112.

The sealing element 114 can be configured to cover or bridge the gap 116between the baseplate 112 and a portion of the substrate support 108.The sealing element 114 can create a seal 118 between chambers 101 and102. The seal 118 can be a contact seal formed through direct contactbetween a portion of the sealing element 114 and another component. Thecontact seal can be a metal-to-metal contact seal. The seal 118 cansubstantially prevent gas from flowing from the loading chamber 101 tothe reaction chamber 102. In this way, the seal 118 can substantiallyfluidly isolate the reaction chamber 102 from the loading chamber 101,such that process gas flow is completely or partially restricted betweenthe reaction chamber 102 and the loading chamber 101. For example, theseal 118 can restrict gas flow through the flow path 901 within the gap116. Embodiments of the sealing elements described herein may beimplemented to restrict flow through other flow paths formed betweenother components, and to cover or seal other gap configurations than ahorizontal or radially extending gap.

As described above, it may be beneficial to provide a seal between theloading chamber 101 and the processing chamber 102 that allows somelimited amount of flow therebetween. In some embodiments, the sealingelement 114 can comprise one or more apertures 120 to provide thesebenefits. The apertures 120 can be any of a number of different shapes,sizes, quantities, and positions through the sealing elements describedherein. As shown, the apertures 120 can be formed in the outer edge ofthe sealing element 114. For example, the apertures 120 can be spaced(e.g., evenly) around the outer edge of the sealing element 114. Theapertures 120 can allow flow path 901 to extend through the sealingelement 114. By allowing a path for gas to flow through the sealingelement 114, and controlling the configuration of the apertures 120, theapertures 120 can be used to control the amount of gas flow allowedbetween chambers 101 and 102. For example, the apertures 120 can controlthe amount of purge gas into the reaction chamber 102 from loadingchamber 101.

Embodiments of the gap, the seal, the sealing element, and othercomponents herein can be advantageously positioned, with respect to eachother or other components to provide improved performance. For example,and with reference to FIGS. 2A and 3A, the exhaust port 107 can bepositioned at a distance D1 from the center of substrate support 108.The seal 118 can be positioned at a distance D2 from the center of thesubstrate support 108. The apertures 120 can be positioned at a distanceD3 from the center of the substrate support 108. Note that the distanceD2 and D3 are shown as being the same in FIG. 3A but they can be thesame or different with respect to each other. The inner edge of thebaseplate 112 can be positioned at a distance D4 from the center of thesubstrate support 108. The gap 116 can be positioned at a distance D5from the center of the substrate support 108. The outer edge of thesubstrate support 108 can be positioned at a distance D6 from the centerof the substrate support 108. An outer edge of the substrate retentionportion 109 can be positioned at a distance D7 from the center of thesubstrate support 108.

In some embodiments, the seal 108 can be positioned at a greater radialdistance D2 from the center of the substrate support 108 than thedistance from the outer edge of the substrate support 108 to the centerD6. In some embodiments, at least one of the apertures 120 and the seal108 can be positioned at a radial distance D3, D2, respectively, that isless than or equal to the distance D1 of the exhaust port 107, relativeto a center of the substrate support 108. In some embodiments, theapertures 120 can be arranged at a greater radial distance D3 from thecenter of the substrate support 108 than the distance D5 to the gap 116.In some embodiments, the exhaust port 107 can be located at a greaterradial distance D1 from the center of the substrate support than adistance from the center of the substrate support to the outermostplurality of gas inlets 105. In some embodiments, the plurality of gasinlets 105 is located radially inwardly from an inside edge of thebaseplate 112 (i.e. the plurality of gas inlets 105 is at a smallerdistance from the center of the substrate support 108 than the distanceD4). In some embodiments, the radial distance between the outer edge ofthe substrate retention portion 109 and the seal 118 (i.e., D2-D7) isbetween about 50 mm to about 65 mm. In some embodiments, the seal 118can be positioned radially from the center of the substrate support 108at a distance D2 of at least 30% or greater than the distance D7 betweenthe center of the substrate support 108 and an outer edge of thesubstrate retention portion 109. In some embodiments, the seal 118 canbe positioned radially from the center of the substrate support 108 at adistance D2 of between 30% and 40% greater than the distance D7 betweenthe center of the substrate support 108 and an outer edge of thesubstrate retention portion 109. The gap 116 can be located at a radialdistance D5 from the center 900 of the substrate support 108 that isless than the radial distance D1 of the reaction chamber outlet 107 fromthe center of the substrate support 108. In some embodiments, the gap116 is located at a radial distance of about 45 mm to about 55 mm awayfrom an outer edge of the substrate retention portion 109. In someembodiments, the gap 116 comprises a width of about 5 mm. The apertures120 can be located at a radial distance D3 from the center of thesubstrate support 108 that is less than the radial distance D1 of thereaction chamber outlet 107 from the center of the substrate support108. In some embodiments, the apertures 120 allow a total of about 50sccm to about 200 sccm of flow through the sealing element.

In some embodiments, the substrate support 108 can comprise an upperportion and a lower portion. In such embodiments, the lower portion canbe a separate piece that is coupled to the upper portion. The upperportion of the substrate support 108 can comprise the substrateretention portion 109. In some embodiments, the lower portion of thesubstrate support 108 can comprise a heating element suitable to heatthe substrate support 108. In some embodiments, the apparatus 100comprises a heat shield 120 disposed beneath the substrate support 108.The heat shield 120 can block at least a portion of heat transfer fromthe heating element to the loading chamber 101. In some embodiments, themounting hardware configured to mount the sealing element can also beused to mount the heat shield to the substrate support.

The sealing element can be positioned with respect to (e.g., attachedto) various components of apparatus 100 suitable to provide thefunctionality described herein. The sealing element 114 can be disposedon, e.g., attached to, the underside of a portion of the substratesupport 108, such as a radially-extending upper portion of the substratesupport 108, as shown. When attached to the substrate support 108, aportion of the sealing element 114 can contact and form the seal 118with the baseplate 112 when the substrate support 108 is in a processingposition. The seal 118 can be formed with the baseplate 112 along asubstantially radially outward portion of the sealing element 114, suchas its outer perimeter or circumference (see also FIGS. 3B and 3C).

To form a stronger seal 118, components of apparatus 100 can beconfigured at advantageous positions with respect to each other, toprovide a “bias” between sealing element 114 and the other component(s)with which it forms seal 118. For example, the portion of the substratesupport 108 on which the sealing element 114 is mounted (such as theunderside surface shown) can be positioned at a slightly higher verticalelevation than the corresponding sealing surface on substrate support108. Such differences in elevation can provide a spring-like force or“bias” between the sealing element 114 and the sealing surface onsubstrate support 108, increasing the strength of seal 118. In someembodiments, the lower portion of substrate support 108 can bepositioned at an elevation between about 1 mm and about 2 mm higher thanthat of the seal 118 on baseplate 112. In some embodiments, the sealingelement 114 may flex when the substrate support is in a processingposition. The sealing element 114 can be made from a resilient material,such as a flexible metal, to provide such flex and bias.

FIG. 3B shows an enlarged view of a portion of FIG. 3A showing the seal118. As discussed above, the sealing element 114 can be attached to aportion of the substrate support 108 (e.g., the underside of the support108), with the seal 118 formed between the point of contact of thesealing element 114 and the baseplate 112. Other embodiments arepossible. For example, a sealing element can be attached to a firstcomponent, with a seal formed at the point of contact between thesealing element and a second component. Thus, for example, the sealingelement can be attached to a stationary component, such as thebaseplate, with a seal formed between the sealing element and thesubstrate support.

In some embodiments, the baseplate 112 comprises a surface with avarying elevation that forms a peak or apex, such as a substantiallynon-planar or curved surface, or a surface with multiple planar surfacesangled to form an apex. In embodiments where the baseplate 112 comprisesa surface with a varying elevation, such as surface 113, the contactseal 118 can be formed at the contacting portion(s) between an apex 113a of the surface 113 and the sealing element 114. In some embodiments, anon-planar surface, or curved surface for engagement and sealing withthe sealing element, can provide mechanical conformance for the contactseal. For example, the sealing element may wrap or conform along acurved surface of the component to which the sealing element iscontacting, to increase the surface area of the seal.

FIG. 3C shows an embodiment similar to FIG. 3B but of an embodimentwhere the surface 113 is curved. The contact seal 118 can be formed atthe contacting portion(s) between the apex 113 a of the curved surface113 and the sealing element 114. In some embodiments where the curvedsurface 113 and/or the sealing element 114 have undergone some amount ofdeformation, the contact seal 118 may exist across a larger portion thana single point when viewed in a cross-section. This deformation mayoccur as the result of force being applied to compress the curvedsurface 113 and sealing element 114 together. Thus, in some embodiments,upon forces being applied between the sealing element 114 and thebaseplate 112, the embodiment shown in FIG. 3C may result in aconfiguration similar to that shown in FIG. 3B.

FIG. 3D shows a top view of the sealing element 114 according to anembodiment of the semiconductor processing apparatus 100. Referring toboth FIGS. 3B and 3C, the apertures 120 can be located around aperimeter (e.g., the peripheral edge) of the sealing element 114. Insome embodiments, the apertures 120 can each be configured to extendradially across the apex 113 a of the surface 113 when apparatus 100 isin a processing position and seal 118 is formed (FIG. 3B). The apertures120 can be configured such that at least a portion of the radiallyextending length of the apertures (shown as dimension “L”) is on theradially inward side of the apex of the surface 113. The apertures 120can allow gas flow through the sealing element 114 and flow path 901,within the gap 116 through at least this portion of the apertures on theradially inward side of the apex 113 a of the surface 113. The aperturescan be positioned at a radial position that is approximately the same asor greater than the radial position of the gap 116.

In some embodiments, the apertures can comprise slots extending throughthe sealing element 114, although many different shapes are suitable.For example, apertures 120 are shown as slots with a width Wd and lengthL1. The contact seal 118 is depicted in FIG. 3C by a dotted line forminga first circumference that shows where the apex 113 a of the surface 113contacts the sealing element 114 according to some embodiments. A secondcircumference extending through apertures 120 around the sealing element114 will generally be less than the first circumference formed by theshape of the contact seal 118. In some embodiments, the totalcircumference of the sealing element 114 that comprises apertures 120will be far less than the total circumference of the sealing element 114that comprises the contact seal 118. In some embodiments, thecircumference of the sealing element 114 that comprises the contact seal118 is 500 to 550 times greater than the circumference of the sealingelement 114 that comprises the apertures 120. In some embodiments, thesealing element 114 comprises a total of 12 apertures 120. In someembodiments, the apertures 120 are each about 5.5 mm long and about 0.2mm wide. However, a person of skill in the art will recognize that theapertures 120 can come in a variety of different numbers and sizes. Insome embodiments, the total effective area of the apertures 120 isbetween 4 mm² and 6 mm². In some embodiments, the total effective areaof the apertures 120 is about 4.8 mm² where the total effective area isequal to the area of the apertures that is radially inward from the seal118. As shown, the effective area is defined by the dimension L (FIGS.3B and 3C) and the width W of the apertures 120 (FIG. 3C). In someembodiments, the total area of the apertures 120 is about 13.2 mm².

In some embodiments, the sealing element 114 can comprise a secondplurality of apertures 220 formed on the sealing element 114. Theapertures 220 can be similarly configured as apertures 120, ordifferently configured. The apertures 220 can be positioned on asubstantially radially inner portion of sealing element 114, compared tothe first plurality of apertures 120. For example, sealing element 114can comprise a substantially annular shape, with the apertures 220spaced (e.g., evenly) around the inner edge of the inner diameter of thesealing element 114. The apertures 220 can reduce compressive stress dueto differences in temperature across the sealing element 114 duringprocessing.

FIGS. 4-7 show embodiments of semiconductor processing apparatuses whichcan include some similar features, and some different features, relativeto those embodiments of apparatus 100 shown in FIGS. 1-3C. It will beappreciated that some aspects of the embodiments shown in FIGS. 4-7 maybe implemented in combination with or instead of some aspects shown inFIGS. 1-3C, and vice versa.

For example, the embodiments shown in FIGS. 4-7 can include a flowcontrol ring 119. In some embodiments, the flow control ring 119 can bean integral or separate component relative to the substrate support 108.The flow control ring 119 may be implemented in order to retrofitexisting equipment with embodiments of the sealing elements and sealsdescribed herein.

The flow control ring 119 can encircle the circumference of thesubstrate support 108. In some embodiments, the flow control ring 119can comprise materials including, but not limited to hastelloy C22 orGrade 2 titanium. The flow control ring 119 can comprise a coating ofAL203. In some embodiments including the embodiments illustrated inFIGS. 4-7, the flow control ring 119 can be removed and replaced by thesubstrate support 108, or portions thereof. In those embodiments, thesubstrate support 108 is larger radially than the embodimentsillustrated, and the substrate support 108 extends to the same distanceradially as the flow control ring 119 would otherwise have extended.

FIG. 4 shows an enlarged cross-sectional view of one embodiment of asealing element 214 the forms a contact seal 118 isolating the loadingchamber 101 from the reaction chamber 102 of a semiconductor processingapparatus 200. In some embodiments, the apparatus 100 can have a flowcontrol ring 119. The flow control ring can be disposed radially betweenthe substrate support 108 and the gap 116. The flow control ring 119 canbe coupled to the substrate support 108.

A sealing element 214 can be disposed on the under-side of the flowcontrol ring 119. Apparatus 200 and sealing element 214 can be similarto apparatus 100 and sealing element 114, with some differences. Forexample, apertures 120 can be positioned on the sealing element 214 at aradial position that is less than that of the gap 116. A verticallyextending gap 117 can be disposed between the flow control ring 119 andsealing element 114. In some embodiments, the vertical gap 117 can becreated by moving the lower surface of the flow control ring 119 to ahigher elevation than the baseplate 112, and flexing the sealing element214 away from the lower surface of the flow control ring 119. In someembodiments with the vertical gap 117, a flowpath 902 can be formedextending through gap 116, the vertical gap 117, and apertures 120, toallow flow between the loading chamber 101 and the reaction chamber 102.Although illustrated with a flow control ring 119, the embodimentsillustrated in FIG. 4 and described herein can also comprise an extendedsubstrate support 108 instead of the flow control ring 119.

FIG. 5 shows an enlarged cross-sectional view of an embodiment of asealing element 314 forming a contact seal 118 isolating the loadingchamber 101 from the reaction chamber 102 of a semiconductor processingapparatus 300. In some embodiments, the contact seal 118 can be disposedon the upper side of the gap 116. The sealing element 314 can be affixedto the baseplate 112 (e.g., to an upper surface of baseplate 112). Thesealing element 314 can also contact the flow control ring 119 and formthe contact seal 118 when the apparatus 300 is in a processing position.By having the sealing element 314 disposed on the upper side of the gap116, this design can take advantage of high pressure in the reactorchamber 102 that can apply downward pressure on the sealing element 314.This downward pressure on the sealing element 314 can create a strongerseal. Although not illustrated in FIG. 4, the sealing element 314 cancomprise apertures 120 disposed over the gap 116 (e.g., at a similarradial position). Although illustrated with a flow control ring 119, theembodiments illustrated in FIG. 5 and described herein can also comprisean extended substrate support 108 instead of the flow control ring 119.

FIG. 6 shows an enlarged view of a contact seal 118 according to oneembodiment of a semiconductor processing apparatus 400. Apparatus 400can comprise bellows 218. In some embodiments, the baseplate 112 cancomprise bellows 218. The bellows 218 can contact the sealing element414. The contact seal 118 can be formed at the contact between thebellows 218 and the sealing element 414. In some embodiments, thebellows 218 can be formed integrally with or attached to the sealingelement 414, and the seal 118 can be formed between the bellows and thebaseplate 112. In some embodiments, the bellows 218 can comprise threeconvolutions. The bellows 218 can be compressible. The compression ofthe bellows 218 can provide compliance for the contact seal 118. In someembodiments, the bellows 218 can be compressed up to 1 mm-2 mm. Althoughnot illustrated in FIG. 5, the sealing element 414 and/or the bellows218 can comprise apertures, similar to apertures 120 in the otherembodiments, so that gas may flow through the sealing element 414. Theseapertures can be disposed on the peripheral edge of the sealing element414 or somewhere more radially inward, for example, under the gap 116.Although illustrated with a flow control ring 119, the embodimentsillustrated in FIG. 6 and described herein can also comprise an extendedsubstrate support 108 instead of the flow control ring 119.

FIG. 7 shows an enlarged, cross sectional view of a seal 318 isolatingthe loading chamber 101 from the reaction chamber 102 according to anembodiment of a semiconductor processing apparatus 500. In someembodiments, the sealing element 314 can comprise an elastic orelastomeric material. In some embodiments, the apparatus 500 cancomprise a pneumatic input 317. The pneumatic input 317 canpneumatically actuate the sealing element 314. The pneumatic input 317can actuate the sealing element 314 by providing pressurized gas to thesealing element 314. In some embodiments, the pneumatic input 317 canextend through a portion of the apparatus 500. In some embodiments, thepneumatic input 317 can extend through the baseplate 112. In someembodiments, the apparatus will comprise a gap 316 where gas couldpossibly flow between the loading chamber 101 and the reaction chamber102 when the substrate support 108 and moving element 110 are in aloading position. The sealing element 314 can span across the gap 316between the baseplate 112 and the flow control ring 119 when the sealingelement 314 is actuated, or in an engaged or pressurized configuration.In some embodiments, gas can flow between the loading chamber 101 andthe reaction chamber 102 through gaps in the labyrinth formed betweenthe flow control ring 119 and the baseplate 112. The apparatus 500 cancomprise a seal 318. The seal 318 can be formed where the sealingelement 314 contacts the flow control ring 119. In some embodiments, theapparatus 100 can comprise a second seal 320 where the substrate support108 and the flow control ring 119 engage in the loading position. Thesecond seal 320 can comprise a metal to metal seal. Although illustratedwith a flow control ring 119, the embodiments illustrated in FIG. 7 anddescribed herein can also comprise an extended substrate support 108instead of the flow control ring 119. A similar pneumatic actuator suchas that is shown in FIG. 7 can be implemented in other embodimentsdescribed herein. For example, a pneumatic input and pneumatic sealingelement similar to those in FIG. 7 could be extended horizontally fromthe baseplate 112 to create a seal against the substrate support 108 inthe embodiments shown in FIGS. 3A-3C.

The foregoing description details some embodiments of the invention. Itwill be appreciated, however, that no matter how detailed the foregoingappears in text, the invention can be practiced in many ways. As is alsostated above, it should be noted that the use of particular terminologywhen describing certain features or aspects of the invention should notbe taken to imply that the terminology is being re-defined herein to berestricted to including any specific characteristics of the features oraspects of the invention with which that terminology is associated. Thescope of the invention should therefore be construed in accordance withthe appended claims and any equivalents thereof.

1. A semiconductor processing apparatus comprising: a reaction chambercomprising a baseplate including an opening; a moveable substratesupport configured to support a substrate; a movement element configuredto move a substrate held on the substrate support towards the opening ofthe baseplate; a plurality of gas inlets positioned above and configuredto direct gas downwardly towards the substrate support; and a sealingelement configured to form a seal between the baseplate and thesubstrate support, the seal positioned at a greater radial distance froma center of the substrate support than an outer edge of the substratesupport.
 2. The apparatus of claim 1, further comprising a plurality ofapertures extending through the sealing element, the aperturesconfigured to provide a flow path between a position below the sealingelement and a position above the sealing element.
 3. The apparatus ofclaim 1, wherein the sealing element comprises metal.
 4. The apparatusof claim 3, wherein the seal comprises a metal to metal contact betweenthe sealing element and at least one of the baseplate and the substratesupport.
 5. (canceled)
 6. (canceled)
 7. (canceled)
 8. The apparatus ofclaim 1, further comprising an exhaust port, wherein at least one of theapertures and the seal is positioned at a radial distance that is lessthan or equal to the exhaust port, relative to a center of the substratesupport.
 9. The apparatus of claim 8, further comprising a gap extendingradially between the substrate support and the baseplate, wherein theapertures are arranged at a greater radial distance from the center ofthe substrate support than the gap.
 10. The apparatus of claim 9,wherein the seal is formed without a substantial vertical gap betweenthe substrate support and the baseplate.
 11. The apparatus of claim 10,wherein the exhaust port is located at a greater radial distance fromthe center of the substrate support than the plurality of gas inlets.12. (canceled)
 13. (canceled)
 14. The apparatus of claim 11, wherein theexhaust port comprises an exhaust ring extending around the substratesupport.
 15. (canceled)
 16. The apparatus of claim 1, wherein eachaperture comprises a slot.
 17. (canceled)
 18. (canceled)
 19. (canceled)20. The apparatus of claim 1, wherein the apertures are configured toallow about 50 sccm to about 200 sccm of flow through the sealingelement when the seal is formed between the baseplate and the substratesupport.
 21. The apparatus of claim 1, wherein the substrate supportcomprises an upper portion and a lower portion, wherein the sealingelement is affixed to an underside of the upper portion of the substratesupport.
 22. (canceled)
 23. (canceled)
 24. The apparatus of claim 1,wherein the baseplate comprises a surface, the surface including anapex, the seal formed between the apex and the sealing element, whereinthe apertures extend radially across the apex.
 25. The apparatus ofclaim 24, wherein the total circumference where the curved surfacecontacts the sealing element is greater than the total circumference ofthe apertures.
 26. (canceled)
 27. The apparatus of claim 1, wherein thesealing element is pneumatically actuated.
 28. A semiconductorprocessing apparatus comprising: a reaction chamber comprising abaseplate including an opening; a moveable substrate support configuredto support a substrate; a movement element configured to move asubstrate held on the substrate support towards the opening of thebaseplate; and a metal sealing element extending around the substratesupport and configured to form a seal between the baseplate and thesubstrate support, wherein a plurality of apertures extend through thesealing element, the apertures configured to provide a flow path betweena position below the sealing element to a position above the sealingelement.
 29. The apparatus of claim 28, wherein the seal comprises ametal to metal contact between the sealing element and at least one ofthe baseplate and the substrate support.
 30. The apparatus of claim 29,wherein the baseplate comprises bellows, wherein the seal is formedbetween the sealing element and the bellows.
 31. (canceled) 32.(canceled)
 33. (canceled)
 34. (canceled)
 35. (canceled)
 36. Theapparatus of claim 28, further comprising a plurality of gas inletspositioned above and configured to direct gas downwardly towards thesubstrate portion.
 37. The apparatus of claim 36, wherein the pluralityof gas inlets is located radially inwardly from an inside edge of thebaseplate.
 38. The apparatus of claim 37, wherein the plurality of gasinlets is arranged in a showerhead formation.
 39. (canceled)
 40. Theapparatus of claim 38, wherein the plurality of gas inlets is furtherconfigured to direct gas substantially perpendicular to a substantiallyplanar upper surface of the substrate support.
 41. The apparatus ofclaim 28, wherein each aperture comprises a slot.
 42. The apparatus ofclaim 41, wherein the plurality of apertures are spaced around an outeredge of the sealing element.
 43. (canceled)
 44. The apparatus of claim42, further comprising a second plurality of slots arranged on aradially inner portion of the sealing element.
 45. (canceled) 46.(canceled)
 47. (canceled)
 48. The apparatus of claim 28, wherein thesubstrate support comprises a substrate retention portion, wherein aradial distance between an outer edge of the substrate retention portionand the seal is between about 50 mm to about 65 mm.
 49. (canceled) 50.(canceled)
 51. The apparatus of claim 28, wherein a total effective areaof a portion of the apertures which is located radially inwardly fromthe seal is in a range of about 4 mm² to about 6 mm².
 52. Asemiconductor processing apparatus comprising: a reaction chambercomprising a baseplate including an opening; a moveable substratesupport comprising a substrate retention portion configured to support asubstrate; a movement element configured to move a substrate held on thesubstrate support towards the opening of the baseplate; and a sealingelement configured to form a seal between the baseplate and thesubstrate support, the seal positioned radially from a center of thesubstrate support at a distance at least 30% or greater than thedistance between the center of the substrate support and an outer edgeof the substrate retention portion, wherein a plurality of aperturesextend through the sealing element, the apertures configured to providea flow path between a position below the sealing element to a positionabove the sealing element.